Semiconductor wafer carriers, also referred to as semiconductor wafer cassettes, are known in the art. Such carriers are typically utilized for storage, transportation and processing of semiconductor wafers. The semiconductor wafer carriers are configured to carry a plurality of semiconductor wafers or workpieces. In particular, the semiconductor wafer carriers usually include a plurality of slots individually configured to receive a single semiconductor wafer.
Typically, the semiconductor wafers are arranged within the wafer carrier outside of a semiconductor processor. The semiconductor wafer carrier is thereafter transported, with the semiconductor wafers inside, into the processing apparatus. Some semiconductor processors are typically configured to process the semiconductor wafers within the wafer carrier.
During most wafer processing steps, it is preferred or necessary to completely expose the front surfaces of the semiconductor wafers being processed to ensure complete processing. Therefore, the front surfaces of the semiconductor wafers being processed are spaced from other wafers or wafer carrier surfaces to facilitate complete exposure of the surfaces to processing fluids. In the prior art, semiconductor wafers are arranged with their front surfaces facing in one direction. Additionally, one empty slot is usually provided intermediate immediately adjacent semiconductor wafers to facilitate exposure of the respective front surfaces of the wafers to the processing fluids.
Conventional spacing or arrangement of the semiconductor wafers reduces the number of semiconductor wafers which can be loaded into a wafer carrier. Accordingly, fewer semiconductor wafers are processed within a single wafer carrier reducing processing throughput.
In addition, the diameter of semiconductor wafers continues to increase as the demand for higher chip and die yields from a single semiconductor wafer increases. Providing semiconductor wafers having increased diameters has resulted in a need for improved processing methods and apparatus.